Evaluation of the Antibacterial Properties of Turmeric-, Synephrine- and Yohimbine-Containing Dietary Supplements Used by Bodybuilders

Among the substances and preparations used in bodybuilding as potential or auxiliary ergogenic agents, particular attention should be paid to plant-based, specifically turmeric, synephrine and yohimbine, preparations due to their known antimicrobial properties. Despite the known antibacterial properties of individual active components, the antimicrobial activity of commercial ergogenic foods and sports supplements formulated with them remains insufficiently studied. Therefore, the aim of this study was to study the in vitro antibacterial activity of commercial dietary supplements with turmeric, synephrine and yohimbine used by bodybuilders against some representatives of sanitary indicator bacteria—Escherichia coli and Staphylococcus aureus. The study used commercial dietary supplements freely available in Ukraine, which, according to the manufacturers, contained turmeric, Citrus aurantium extract (with synephrine) and yohimbine. Gram-negative E. coli ATCC 35218 and Gram-positive S. aureus ATCC 29213 were used as model test systems. Antibacterial susceptibility was assessed by a spot-on-lawn antibacterial assay (on MPA) and a method with a liquid nutrient medium (in MPB), with subsequent statistical processing of the results. The preliminary results obtained demonstrate moderate antibacterial activity of the studied food supplements used by athletes, primarily turmeric- and synephrine-containing supplements, against the studied test bacterial cultures. Given the results obtained, it is advisable to conduct further research on dietary supplements containing turmeric and synephrine to evaluate their antibacterial potential, which requires further study, particularly involving a broader range of test strains. Future studies should focus on specific molecular mechanisms of action, establishing effective concentrations, and assessing safety during long-term use. Particular attention should be paid to potential interactions with commonly used antibacterial drugs and to the risks of antibiotic resistance.